#!/usr/bin/env python
############################################################################
#
#   Copyright (C) 2012 PX4 Development Team. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in
#    the documentation and/or other materials provided with the
#    distribution.
# 3. Neither the name PX4 nor the names of its contributors may be
#    used to endorse or promote products derived from this software
#    without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
############################################################################

#
# Serial firmware uploader for the PX4FMU bootloader
#
# The PX4 firmware file is a JSON-encoded Python object, containing
# metadata fields and a zlib-compressed base64-encoded firmware image.
#
# The uploader uses the following fields from the firmware file:
#
# image
#	The firmware that will be uploaded.
# image_size
#	The size of the firmware in bytes.
# board_id
#	The board for which the firmware is intended.
# board_revision
#	Currently only used for informational purposes.
#

import sys
import argparse
import binascii
import serial
import os
import struct
import json
import zlib
import base64
import time
import array

from sys import platform as _platform

class firmware(object):
	'''Loads a firmware file'''

	desc = {}
	image = bytes()
	crctab = array.array('I', [
		0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
		0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
		0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
		0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
		0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
		0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
		0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
		0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
		0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
		0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
		0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
		0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
		0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
		0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
		0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
		0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
		0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
		0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
		0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
		0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
		0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
		0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
		0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
		0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
		0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
		0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
		0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
		0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
		0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
		0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
		0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
		0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d ])
	crcpad = bytearray('\xff\xff\xff\xff')

	def __init__(self, path):

		# read the file
		f = open(path, "r")
		self.desc = json.load(f)
		f.close()

		self.image = bytearray(zlib.decompress(base64.b64decode(self.desc['image'])))

		# pad image to 4-byte length
		while ((len(self.image) % 4) != 0):
			self.image.append('\xff')

	def property(self, propname):
		return self.desc[propname]

	def __crc32(self, bytes, state):
		for byte in bytes:
			index = (state ^ byte) & 0xff
			state = self.crctab[index] ^ (state >> 8)
		return state

	def crc(self, padlen):
		state = self.__crc32(self.image, int(0))
		for i in range(len(self.image), (padlen - 1), 4):
			state = self.__crc32(self.crcpad, state)
		return state

class uploader(object):
	'''Uploads a firmware file to the PX FMU bootloader'''

	# protocol bytes
	INSYNC		= chr(0x12)
	EOC		= chr(0x20)

	# reply bytes
	OK		= chr(0x10)
	FAILED		= chr(0x11)
	INVALID		= chr(0x13)	# rev3+

	# command bytes
	NOP		= chr(0x00)	# guaranteed to be discarded by the bootloader
	GET_SYNC	= chr(0x21)
	GET_DEVICE	= chr(0x22)
	CHIP_ERASE	= chr(0x23)
	CHIP_VERIFY	= chr(0x24)	# rev2 only
	PROG_MULTI	= chr(0x27)
	READ_MULTI	= chr(0x28)	# rev2 only
	GET_CRC		= chr(0x29)	# rev3+
	REBOOT		= chr(0x30)
	
	INFO_BL_REV	= chr(1)	# bootloader protocol revision
	BL_REV_MIN	= 2		# minimum supported bootloader protocol 
	BL_REV_MAX	= 3		# maximum supported bootloader protocol 
	INFO_BOARD_ID	= chr(2)	# board type
	INFO_BOARD_REV	= chr(3)	# board revision
	INFO_FLASH_SIZE	= chr(4)	# max firmware size in bytes

	PROG_MULTI_MAX	= 60		# protocol max is 255, must be multiple of 4
	READ_MULTI_MAX	= 60		# protocol max is 255, something overflows with >= 64

	def __init__(self, portname, baudrate):
		# open the port, keep the default timeout short so we can poll quickly
		self.port = serial.Serial(portname, baudrate, timeout=0.25)

	def close(self):
		if self.port is not None:
			self.port.close()

	def __send(self, c):
#		print("send " + binascii.hexlify(c))
		self.port.write(str(c))

	def __recv(self, count = 1):
		c = self.port.read(count)
		if len(c) < 1:
			raise RuntimeError("timeout waiting for data")
#		print("recv " + binascii.hexlify(c))
		return c

	def __recv_int(self):
		raw = self.__recv(4)
		val = struct.unpack("<I", raw)
		return val[0]

	def __getSync(self):
		self.port.flush()
		c = self.__recv()
		if c is not self.INSYNC:
			raise RuntimeError("unexpected 0x%x instead of INSYNC" % ord(c))
		c = self.__recv()
		if c == self.INVALID:
			raise RuntimeError("bootloader reports INVALID OPERATION")
		if c == self.FAILED:
			raise RuntimeError("bootloader reports OPERATION FAILED")
		if c != self.OK:
			raise RuntimeError("unexpected response 0x%x instead of OK" % ord(c))

	# attempt to get back into sync with the bootloader
	def __sync(self):
		# send a stream of ignored bytes longer than the longest possible conversation
		# that we might still have in progress
#		self.__send(uploader.NOP * (uploader.PROG_MULTI_MAX + 2))
		self.port.flushInput()
		self.__send(uploader.GET_SYNC 
				+ uploader.EOC)
		self.__getSync()
		
#	def __trySync(self):
#		c = self.__recv()
#		if (c != self.INSYNC):
#			#print("unexpected 0x%x instead of INSYNC" % ord(c))
#			return False;
#		c = self.__recv()
#		if (c != self.OK):
#			#print("unexpected 0x%x instead of OK" % ord(c))
#			return False
#		return True

	# send the GET_DEVICE command and wait for an info parameter
	def __getInfo(self, param):
		self.__send(uploader.GET_DEVICE + param + uploader.EOC)
		value = self.__recv_int()
		self.__getSync()
		return value

	# send the CHIP_ERASE command and wait for the bootloader to become ready
	def __erase(self):
		self.__send(uploader.CHIP_ERASE 
				+ uploader.EOC)
		# erase is very slow, give it 10s
		deadline = time.time() + 10
		while time.time() < deadline:
			try:
				self.__getSync()
				return
			except RuntimeError as ex:
				# we timed out, that's OK
				continue

		raise RuntimeError("timed out waiting for erase")

	# send a PROG_MULTI command to write a collection of bytes
	def __program_multi(self, data):
		self.__send(uploader.PROG_MULTI
				+ chr(len(data)))
		self.__send(data)
		self.__send(uploader.EOC)
		self.__getSync()
		
	# verify multiple bytes in flash
	def __verify_multi(self, data):
		self.__send(uploader.READ_MULTI
				+ chr(len(data))
				+ uploader.EOC)
		self.port.flush()
		programmed = self.__recv(len(data))
		if programmed != data:
			print("got    " + binascii.hexlify(programmed))
			print("expect " + binascii.hexlify(data))
			return False
		self.__getSync()
		return True
		
	# send the reboot command
	def __reboot(self):
		self.__send(uploader.REBOOT
				+ uploader.EOC)
		self.port.flush()

		# v3+ can report failure if the first word flash fails
		if self.bl_rev >= 3:
			self.__getSync()

	# split a sequence into a list of size-constrained pieces
	def __split_len(self, seq, length):
    		return [seq[i:i+length] for i in range(0, len(seq), length)]

	# upload code
	def __program(self, fw):
		code = fw.image
		groups = self.__split_len(code, uploader.PROG_MULTI_MAX)
		for bytes in groups:
			self.__program_multi(bytes)

	# verify code
	def __verify_v2(self, fw):
		self.__send(uploader.CHIP_VERIFY
				+ uploader.EOC)
		self.__getSync()
		code = fw.image
		groups = self.__split_len(code, uploader.READ_MULTI_MAX)
		for bytes in groups:
			if (not self.__verify_multi(bytes)):
				raise RuntimeError("Verification failed")

	def __verify_v3(self, fw):
		expect_crc = fw.crc(self.fw_maxsize)
		self.__send(uploader.GET_CRC
				+ uploader.EOC)
		report_crc = self.__recv_int()
		self.__getSync()
		if report_crc != expect_crc:
			print("Expected 0x%x" % expect_crc)
			print("Got      0x%x" % report_crc)
			raise RuntimeError("Program CRC failed")

	# get basic data about the board
	def identify(self):
		# make sure we are in sync before starting
		self.__sync()

		# get the bootloader protocol ID first
		self.bl_rev = self.__getInfo(uploader.INFO_BL_REV)
		if (self.bl_rev < uploader.BL_REV_MIN) or (self.bl_rev > uploader.BL_REV_MAX):
			print("Unsupported bootloader protocol %d" % uploader.INFO_BL_REV)
			raise RuntimeError("Bootloader protocol mismatch")

		self.board_type = self.__getInfo(uploader.INFO_BOARD_ID)
		self.board_rev = self.__getInfo(uploader.INFO_BOARD_REV)
		self.fw_maxsize = self.__getInfo(uploader.INFO_FLASH_SIZE)

	# upload the firmware
	def upload(self, fw):
		# Make sure we are doing the right thing
		if self.board_type != fw.property('board_id'):
			raise RuntimeError("Firmware not suitable for this board")
		if self.fw_maxsize < fw.property('image_size'):
			raise RuntimeError("Firmware image is too large for this board")

		print("erase...")
		self.__erase()

		print("program...")
		self.__program(fw)

		print("verify...")
		if self.bl_rev == 2:
			self.__verify_v2(fw)
		else:
			self.__verify_v3(fw)

		print("done, rebooting.")
		self.__reboot()
		self.port.close()
	

# Parse commandline arguments
parser = argparse.ArgumentParser(description="Firmware uploader for the PX autopilot system.")
parser.add_argument('--port', action="store", required=True, help="Serial port(s) to which the FMU may be attached")
parser.add_argument('--baud', action="store", type=int, default=115200, help="Baud rate of the serial port (default is 115200), only required for true serial ports.")
parser.add_argument('firmware', action="store", help="Firmware file to be uploaded")
args = parser.parse_args()

# Load the firmware file
fw = firmware(args.firmware)
print("Loaded firmware for %x,%x, waiting for the bootloader..." % (fw.property('board_id'), fw.property('board_revision')))

# Spin waiting for a device to show up
while True:
	for port in args.port.split(","):

		#print("Trying %s" % port)

		# create an uploader attached to the port
		try:
			if "linux" in _platform:
			# Linux, don't open Mac OS and Win ports
				if not "COM" in port and not "tty.usb" in port:
					up = uploader(port, args.baud)
			elif "darwin" in _platform:
				# OS X, don't open Windows and Linux ports
				if not "COM" in port and not "ACM" in port:
					up = uploader(port, args.baud)
			elif "win" in _platform:
				# Windows, don't open POSIX ports
				if not "/" in port:
					up = uploader(port, args.baud)
		except:
			# open failed, rate-limit our attempts
			time.sleep(0.05)

			# and loop to the next port
			continue

		# port is open, try talking to it
		try:
			# identify the bootloader
			up.identify()
			print("Found board %x,%x bootloader rev %x on %s" % (up.board_type, up.board_rev, up.bl_rev, port))

		except:
			# most probably a timeout talking to the port, no bootloader
			continue

		try:
			# ok, we have a bootloader, try flashing it
			up.upload(fw)

		except RuntimeError as ex:

			# print the error
			print("ERROR: %s" % ex.args)

		finally:
			# always close the port
			up.close()

		# we could loop here if we wanted to wait for more boards...
		sys.exit(0)
